Readily disassembled electric fan



y 1969 HIROSHI SUZUKI L READILY DISASSEMBLED ELECTRIC FAN Sheet of 3 Filed Dec. 7, 1967 FIG.I

y 1969 HIROSHI SUZUKI ETAL $446,429

READILY DISASSEMBLED ELECTRIC FAN Filed Dec. 7, 1967 Sheet L of 3 38 FIG.2

y 27, 1959 HIROSHI SUZUKI E L 3,446,429

READILY DISASSEMBLED ELECTRIC FAN- Sheet i of 3 Filed Dec. 7, 1967 FIG. 4

Waited U.S. Cl. 230-259 4 Claims ABSTRACT OF THE DISCLOSURE A mounting ring supporting the blade guard of an elec tric fan is dismountably mounted directly on the front boss of the motor frame and held by wedge ridges of a hand rotatable lock ring acting between radial projections fixed to the boss and the mounting ring to press and hold the mounting ring in position against the boss, and a hand rotatable spinner nut or nose piece holds a large diameter fan hub in mounted state on the motor shaft, the fan hub then enclosing and concealing the lock ring. Thus, the fan blade assembly and guard can be easily disassembled and reassembled by hand without the use of a tool.

This invention relates generally to electric fans and more particularly to a new and improved electric fan of a construction whereby the propeller or blade assembly and the blade guard surrounding the blade assembly can be readily dismounted and remounted.

A particular feature of the electric fan of the invention is that the blade guard can be readily attached to and detached from the frame of the fan motor simply by turning a lock ring by hand after removal of the blade assembly by an equally simple procedure of merely unscrewing a hand rotatable spinner nut.

In general, the blade assembly of an electric fan is fixed by a screw to the rotor shaft of an electric motor, and the guard surrounding the blade assembly is mounted on and secured to the motor frame or motor casing by a plurality of screws. For this reason, a tool such as a screwdriver is necessary when these parts are to be disassembled for cleaning various parts of the fan or for packaging. Moreover, this disassembling work is troublesome and difficult, particularly for women.

A prime object of the present invention is to provide an electric fan in which particularly the blade guard can be detaehably fastened to the motor frame by the rotation of a lock ring, whereby the disassembling and reassembling of the fan can be easily and rapidly carried out without the use of a tool such as a screwdriver.

Another object of the invention is to provide mounting means for direct attachment of the blade guard to the motor frame in an electric fan of the above stated character whereby the blade guard can be mounted securely and positively yet dismountably.

Still another object of the invention is to provide an electric fan of the above stated character having a smooth, unbroken outer form, particularly by enclosing the above mentioned lock ring within the skirt part of the hub of the blade assembly in mounted state on the rotor shaft.

According to the present invention, briefly summarized, there is provided an electric fan of the type having a motor with a rotor shaft and a motor frame with a front boss, a blade assembly of blades on a hub mounted on the shaft, and a blade guard enclosing the blade assembly, characterized by the combination therewith of radial projections on the front boss, a mounting member integrally fixed to and supporting the blade guard and detachably fitted onto the front boss, a manually rotatable lock ring atent C 3,446,429 Patented May 27, 1969 ice having inclined surface ridges disengageably engaged be tween the radial projections of the front boss and the mounting member by the rotation of the lock ring thereby to secure the blade guard in dismountable state on the motor frame, and hand operable means for easily mountirlilg and dismounting the blade hub on and from the rotor s aft.

The nature, details, utility, and advantageous features of the invention will be more clearly apparent from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings, in which like parts are designated by like reference numerals.

In the drawings:

FIG. 1 is a side elevation view showing one example of an electric fan embodying the invention;

FIG. 2 is a relatively enlarged side elevation view, with parts cut away, showing the essential parts of the electric fan shown in FIG. 1;

FIG. 3 is a fragmentary perspective view showing the front part of the electric fan shown in FIGS. 1 and 2; and

FIG. 4 is a partial exploded perspective view showing the essential parts of the electric fan shown in FIGS. 1, 2, and 3.

Throughout the present disclosure, directional terms such as front and forward designate the direction from the motor toward the fan blade, i.e., toward the left as viewed in FIGS. 1 and 2, and terms such as rear and rearward designate the opposite direction.

Referring to FIG. 1, the electric fan shown therein is supported on a support structure of known type comprising a base 10, an upright hollow column 11 fixed to the base 10, a movable column 12 movably inserted within the column 11 and provided with means for locking its vertically adjustable position, and a neck piece 13 pivoted for rotation about a horizontal axis afforded by a horizontal pivot 14 supported on the upper end of the movable column 12.

On the neck piece 13, the head 15 of the fan is rotatably supported by a support shaft 17 supporting an electric motor 16 housed within the nacelle or casing 18 of the head, which thereby is rotatable in a horizontal plane when the neck piece 13 is in an attitude such that the shaft 17 is vertical.

The motor 16 has a frame 19 of die-cast aluminum or zinc and enclosed by the above mentioned casing 18 as shown in FIGS. 2 and 3. The front part of the frame 19 is in the form of a cylindrical front boss 20 projecting forward and having a central bore 21 for accommodating the front bearing of the rotor shaft 26. The boss 20 further has a stepped shoulder part 24 at its outer periphery to the rear of its extreme front face, which constitutes a mounting face 22 provided with a plurality of tapped holes 23.

The motor frame 19 supports therewithin an electric motor mechanism 25, the rotor shaft 26 of which extends forward through the front bearing in the boss 20 and has a front extension for mounting the hub of the blade assembly thereon and a threaded front end 27. A pin 28 is passed transversely through the front extension of the shaft 26 at a point spaced apart rearward from the threaded end 27 and projects radially outward from the shaft on opposite sides thereof.

The casing 18 is provided at its front end with a cowling 29 enclosing the front part of the motor frame 19. The cowling 29 is molded from a synthetic resin material or is Tnade by drawing a sheet metal and is fixed to the front face of the frame 19 by screws (not shown) passed through holes in the front part of the cowling 29. The cowling 29 has an annular, forward projecting rim 29a formed around the front periphery thereof and having radially aligned slots 29b adapted to receive the support legs of a rear guard described hereinafter.

For the purpose of providing forwardly projecting fastening lugs around the front periphery of the aforementioned boss 20, a fastening plate 30 is fixed to the front face of the boss 20. More specifically, the plate 30 has a central hole 31 for extension of the shaft 26 therethrough and a plurality of radial projections 32 on its periphery, the projections 32 respectively having forwardly bent flanges on their same sides in the circumferential direction which form fastening lugs 33. The plate 30 is further provided with mounting holes 34 through which screws 35 are passed and screwed into the aforementioned tapped holes 23 to mount the plate 30 on and against the mounting face 22 of the boss 20 of the motor frame 19. Alternatively, the projections 32 and their lugs 33 can be formed integrally on the outer periphery of the boss 20.

The fan propeller or blade assembly 53 is made of metal or a synthetic resin and consists essentially of fan blades 54 and a hub 55 on which the blades 54 are rigidly supported. The hub 55 has an outer shell 58 of the shape of a truncated cone joined by a front web 5511 to a central boss 55b, an annular cavity 57 opens at the rear being formed between the outer shell 58 and the boss 55b. The boss 55!) has a central bore 56 for fitting onto the aforementioned front extension of the rotor shaft 26 for mounting the blade assembly 53. The boss 55b is further provided at its rear face with four recesses 59 which are open at the rear and on their inner sides communicating with the central bore 56 and are spaced 90 degrees of angle apart at the rear rim of the bore 56 in a cross formation.

When the hub 55 is fitted onto the shaft 26, two diametrically opposed recesses 59 engage with the projecting parts of the aforementioned pin 28 passed through the shaft 26, whereby the hub 55 and, therefore, the blade assembly 53 are held fixed in the rearward axial direction and in the rotational directions relative to the shaft 26. The hub 55 is held in this locked state and, moreover, prevented from moving forward by a spinner nut 60 screwed onto the threaded end 27 of the rotor shaft 26. The spinner nut 60 is made of die-cast zinc or of a synthetic resin and has an outer shell with a knurled outer periphery for facilitating turning by hand.

In the mounted state of the blade assembly 53, the rear skirt of the spinner nut 60 contacts or very closely confronts the front peripheral edge of the hub shell 58, the rear skirt of which in turn closely confronts the aforementioned projecting rim 29a of the cowling 29. Furthermore, the external forms of the motor casing 18, the cowling 29, the hub shell 58, and the outer shell of the spinner nut 60 are designed to constitute a unitary form with aesthetically pleasing and aerodynamically fair lines.

The blade assembly 53 and the spinner nut 60 are enclosed by a fan blade guard 36 made up of a rear guard 37 detachably secured to the motor frame 19 and a front guard 38 detachbaly fastened in the conventional manner by clips 61 to the rear guard. The rear guard 37 is of knwon construction at its outer part, which is in the form of an annular basket consisting of radial support legs 39 made of a mild steel wire or angle material, a ring 37a fixed to the outer ends of the legs 39, and a number of guard wires 40 of ring form strung between and supported by the legs 39.

The support legs 39 have respective inner root parts 41 which lie substantially in a single plane perpendicular to the fan axis and are fixed at their innermost ends to a mounting ring 42 with a circular inner edge 43. Cutouts 44 corresponding respectively to the aforementioned radial projections 32 f the fastening plate 30 for clearance in passing thereby are formed in the inner edge 43.

When the rear guard 37 is to be assembled on the fan, the mounting ring 42 is mounted on the boss 20 of the motor frame 19 and held in place as described hereinafter by a tightening lock ring 45 of a synthetic resin or die-cast aluminum or zinc. The lock ring is provided around its outer periphery with knob teeth 46 for facilitating manual gripping and turning and an inner surface 47, in which are formed cutouts 48 corresponding respectively to the aforementioned radial projections 32 of the fastening plate 30. Between the cutouts 48, there are formed ridges 49 of wedge shape with inclined surfaces facing the front whereby the width of each ridge in the axial direction progressively increases in the counterclockwise direction as viewed from the front. A stop 50 is formed at the end of greatest width of each wedge-shaped ridge 49.

The side edges of a cutout 44, for example, the upper cutout 44, of the mounting ring 42 of the rear guard 37 are provided with rearwardly bent flanges or projections 51. In a position corresponding to these projections 51, an engagement slot 52 is formed in the shoulder part 24 provided on the boss 20 of the motor frame 19. When the mounting ring 42 is fitted against the boss 20, the projections 51 of the mounting ring engage with this slot 52 to determine the alignment and positioning of the rear guard 37 relative to the motor frame 19.

When the electric fan is in assembled state, the lock ring 45 and the front part of the boss 20 of the motor frame 19 are disposed within the aforementioned cavity 57 of the hub and are thereby enclosed and concealed within the skirt part of the outer shell 58 of the hub.

The electric fan of the above described organization is assembled in the following manner. First, the rear guard 37 is fitted in place by passing the opening bounded by inner surface 43 of the mounting ring 42 around and along the rotor shaft 26 from the front end thereof toward the rear, clearing the radial projections 32 by causing the cutouts 44 of the mounting ring 42 to pass thereover and thereby, and fitting the mounting ring 42 against the boss 20 of the motor frame 19 in a manner such that the projections 51 engage with the slot 52 in the boss 20, and the mounting ring 42 abuts against the shoulder part 24, whereby the mounting ring alignment and position are determined.

Next, the lock ring 45 is similarly passed around and along the rotor shaft 26 from the front end thereof toward the rear, clearing the radial projections 32 by causing the cutouts 48 of the lock ring 45 to pass thereover and thereby, placing and holding the lock ring 45 firmly against the front face of the mounting ring 42, and, as the lock ring 45 is thus held, turning it in the clockwise direction as viewed from the front. The wedge-shaped ridges 49 of the lock ring 45 are thereupon interposed between respective radial projections 32 and the mounting ring 42, which is thereby pressed tightly against and fixed to the shoulder part 24 of the boss 20 by the wedge action of the ridges 49 produced by the turning of the lock ring 45.

Next, the blade assembly 53 is mounted on the rotor shaft 26 by fitting the propeller hub 55 along the front part of the shaft 26 until two of the recesses 59 engage with the projecting ends of the pin 28 fixed to the shaft 26, then screwing the spinner nut 60 onto the threaded front end 27 of the rotor shaft 26, and tightening the nut 60 thereby to fix the hub 55 of the blade assembly 53 to the rotor shaft 26.

Finally, the front guard 38 is mounted on the front face of the rear guard 37 and fastened thereto by the clips 61. Thus, the blade assembly 53 in mounted state is enclosed by the assembled guard 36, and the assembly is completed.

For disassembly, the above described procedure is reversed. That is, the front guard 38 is first removed, and then spinner nut 68 is unscrewed and removed, whereupon the blade assembly 53 can be pulled forward off the rotor shaft 26. The lock ring 45 is then turned in the counterclockwise direction as viewed from the front to disengage the wedge-shaped ridges 49 from the radial projections 32, and the lock ring 45 is moved forward as the cutouts 44 are passed over and past respective radial projections 32 thereby to remove the lock ring 45. The rear guard 37 can then be disconnected and removed from the motor assembly.

With the fan in this disassembled state, the various parts thereof can be readily and thoroughly cleaned. At the same time, the electric fan in this disassembled state can be conveniently packaged into a compact package for economical storage and/or transportation.

Furthermore, it is to be observed that the so-called streamlined shape of the combination of the motor casing, fan hub, and spinner structure, which conforms to a recent trend in the design of electric fans of the instant class, conveniently makes possible the use of a lock ring 45 and a spinner nut 60 of relatively large diameters, which facilitate the turning thereof by hand.

While one example of inclined surface of the wedgeshaped ridges 49 of the lock ring 45 has been illustrated, it will be apparent that other forms for utilizing the principle of the inclined surface are possible. Furthermore, it will be apparent that, for the means of mounting the blade assembly onto the rotor shaft, modifications of the means described above and as illustrated in the drawings can also be used provided that they afford easy mounting and dismounting of the blade assembly.

What we claim is:

1. An electric fan comprising: an electric motor having a rotor shaft extending toward the front of the fan and a motor frame with a front boss provided with radial projections; a blade assembly having blades radially supported by a hub dismountably mounted on said rotor shaft; a blade guard enclosing said blade assembly and having a mounting member integral therewith detachably fitted onto said front boss of said motor frame; and a manually rotatable lock ring having inclined surface ridges disengageably engaged between said radial projections of the front boss and said mounting member in fitted state by the rotation of said lock ring thereby to secure and hold the blade guard in dismountable state on said motor frame, said hub being readily mounted on and dismounted from the rotor shaft by hand operable means.

2. The electric fan as claimed in claim 1 in which a shouldertpart is provided around the periphery of the front boss of the motor frame for abutment thereagainst of the mounting member of the blade guard.

3. The electric fan as claimed in claim 2 in which an engagement slot is formed in said shoulder part of the front boss, and at least one projection for engagement with said slot is formed in the mounting member of the blade guard.

4. The electric fan as claimed in claim 1 in which the hub of the blade assembly has a cavity on the side thereof facing the motor, and the front part of the front boss of the motor frame and the lock ring in assembled state are disposed and concealed within said cavity when the hub is in mounted state on the rotor shaft.

References Cited UNITED STATES PATENTS 2,923,463 2/1960 Shunkwiler 230-275 2,951,634 9/1960 Koch 230-275 X 3,262,638 7/1966 Militello 230--275 3,347,452 10/ 1967 Radcliffe 230275 X LEONARD H. GERIN, Primary Examiner.

US. Cl. X.R. 230-275 

